1. Technical Field
The present invention relates generally to an apparatus of driving loading, and more particularly to a constant-power power supply apparatus and a method of supplying constant-power power.
2. Description of Related Art
Typically, a constant-power power supply apparatus is used to supplies a specific loading, such as LED (light emitting diode) chip or rechargeable battery, with a constant-power electric power. The conventional constant-power power supply apparatus provides a constant working voltage and a constant working current to the loading only, so that the devices driven by different working voltages and/or working currents need the constant-power power supply apparatus with different specs. For LED chips with the same power, there are a variety of combinations of working voltages and working currents for such LED chips in the present market. For example, the working voltages and working currents for 28 W LED chips includes 80V/350 mA, 56V/500 mA, and 40V/700 mA, and each LED chip needs a specific constant-power power supply apparatus. Therefore, for a manufacturer of LED chips, he has to make a variety of LED chips as well as a variety of constant-power power supply apparatus so that the conventional LED chips are very expensive. In conclusion, the conventional constant-power power supply apparatus still needs to be improved.